A large environment, such as a large building, a factory, or a large house, may have hundreds and thousands of devices that control various systems within the environment. These systems may include lighting systems, heating systems, elevators, and various electronic systems (e.g., monitors, cameras, and CD players). In such large environments, the controlling of the devices can be cumbersome. Each device may provide a control panel through which the device can be controlled. For example, a CD player may have a control panel on it for controlling the device to eject the CDs, to pause the CD, and so on. These devices may also provide an electronic interface through which the device can be controlled by a computer. A computer that is connected to the electronic interface may provide a user interface through which a user can control the device. These devices may be connected to a communications channel, such as a serial link, so that a central computer can control the devices. The connections to the communications channel may be direct when the device has an embedded interface to the communications channel or may be indirect by being connected to a computer system that is then connected to the communications channel. To control the devices from a central location, a user interface for each device needs to be developed for the computer at the central location. The development of the user interfaces for controlling these devices from a remote location can be expensive and time-consuming. Moreover, whenever new devices are added to the environment, new user interfaces also need to be developed so that the new devices can be controlled remotely.
In certain environments, such as a large house, it may be desirable to remotely control the devices from various locations rather than at a central location. In addition, it may be desirable to allow control of only certain devices from each location so that the user interface can be customized to the devices that can be controlled. For example, within a media room it may be desirable to control all the devices within that room and to control certain devices (e.g., lights) in adjacent rooms. The use of the same user interface, which is intended for controlling all the devices in an environment from a central location, would be cumbersome if used at multiple locations where it is only desired to control certain devices. For example, it would be cumbersome to have a user interface for controlling all devices within a large building, when only one type of device (e.g., a light switch) should logically be controlled from that location.